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Monday, February 10, 2014

Screening for Toxic Chemicals

Ken Ward, as usual, had a very
interesting article at WVGazette.com this weekend about the continued
controversy over what constitutes a ‘safe level’ of Crude MCHM in the drinking
water of Charleston, WV. The combination of politics, analytical chemistry and
chemphobia is never a pretty picture and when you add in drinking water safety
you have a perfect storm of controversy.

The CDC last week published a rather detailed
technical discussion of how they came, a second time, to set the safe
drinking water limits at 1 ppm. There is also a rather detailed, and even more
technical, page
of information about 4-Methylcyclohexanemethanol, a major constituent of
Crude MCHM, available from the National Institute of Health.

There is a very legitimate debate about the methodology that
the CDC employed when they established the 1 ppm safe drinking water limit. I
happen to agree with their method, but there is more than a little element of
judgment call involved and that certainly calls for a public discussion.
Unfortunately, the CDC was pressed for an answer by many of the same people who
are now questioning the decision.

The problem, was of course, that there was an ongoing
problem with over 300,000 people not being able to bathe, wash their clothes or
prepare food with the water in their municipal water system. There was a great
deal of political pressure to come up with a safe drinking limit based upon limited
evidence. Any way the CDC went; setting the current limit, setting a stricter
limit, or calling for more information; would have been met with legitimate
complaints.

This is not a decision that should be made when there are
problems with a contaminated water system. This is process that should be
clearly established by a public rule making process that allows for a complete
discussion of all of the ramifications that affect the decision and the
outcomes based upon that decision.

This is why I described a process in my alternative to S1961 by which there would be a standard method established for determining the
safe level of a contaminant in drinking water and a requirement for minimum
standards for toxicity testing for chemicals that are likely to contaminate
drinking water.

While there is certainly a technical component for testing
and limit setting discussion, it is mainly a political decision. Political
discussions take time to resolve. They should not be made in the heat of the
moment when people are in desperate straits; seeking an immediate answer to a
complicated problem.

Finally, we have to acknowledge that there is no perfect
answer to the question of what is a safe exposure level. There are just too
many differences in each of our bodies for there to be a single answer. This is
why there should be a government funded and run epidemiological study of every
instance where a chemical like this gets into a public water supply. We know that
hindsight is 20-20; but it is only clear when a detailed and dispassionate
investigation is made.

It will only be through such studies that we will be able to
refine the rules and standards by which we determine what are safe levels of
contamination in public drinking water.

About Me

I spent 15 years in the US Army as an Infantry NCO. After getting out of the Army I started working in the chemical industry, getting my BSc Chemistry degree while working as a technician. I spent 12 years working as a process chemist in a specialty chemical company. Most recently I worked as a QA/R&D Manager in a specialty chemical manufacturing facility. Currently I am working as a freelance writer.